Fast dissolving pharmaceutical dosage forms which are designed to release an active ingredient in the oral cavity are well known and can be used to deliver a wide range of drugs (Critical Reviews in Therapeutic Drug Carrier Systems, 21(6):433-475 (2004); Seager H. (1998), J. Phar. Pharmacol 50:375-382; Bandari et al. (January 2008), Asian Journal of Pharmaceutics 2-11).
In a fast dissolving dosage form, a drug may physically be trapped in a matrix composed of e.g. mannitol and fish gelatin (EP 1501534; EP1165053), modified starch (U.S. Pat. No. 6,509,040), pullulan in combination with an amino acid (EP1803446), or maltodextrin in combination with sorbitol (US2004/0228919). The solution, suspension or dispersion of the drug and the carrier material may be filled into blister cavities, frozen and thereafter lyophilized. However, dosage forms produced in this manner are mostly fragile and brittle, have limited physical strength, and cannot withstand any pressure. In addition, dosage units so produced are difficult to pack and unpack.